[Effect of fenestration of the cochlea on the vibration of the round window membrane]. / Effekt der Promontorialfensterung auf die Schwingung der Rundfenstermembran - experimentelle Studie.

Drilling a promontory window and coupling an FMT into the scala tympani may be a surgical alternative to stapes surgery in obliterative tympanosclerosis. Aim of this experimental study on human temporal bones was to measure changes of the acoustic transfer function from the tympanic membrane to the round window membrane after drilling a promontory window and insertion of a floating mass transducer.Laser vibrometry and acoustic measurements were performed on 11 temporal bone preparations equipped with a microphone attached to the round window. Calibrations were carried out to allow determination of SPLs affecting the cochlea after drilling a promontory window leaving the membranous inner ear intact and after insertion of an FMT into the cavity (with or without slight pressure).Drilling a promontory window does influence the transfer function. Insertion of the FMT with additional slight pressure further changes the transfer function.The presence of a promontory window changes the acoustic transfer function to the round window. Further investigations are needed to correlate the qualitative results with the audiological results after "third window vibroplasty" (inserted floating mass transducer without stimulation).

[Mastoid obliteration with a highly porous bone grafting material in combination with cartilage]. / Mastoidhöhlenobliteration mit einem hochporösen Knochenaufbaumaterial (NanoBone®) und Conchaknorpel.

BACKGROUND: An open mastoid cavity might lead to various problems for the patient. Chronic inflammation of the cavity with secretion, changes in the acoustic behavior, vertigo in restricted situations and an impaired self-cleaning function might affect the patient. For surgical treatment reducing of the size of such cavities have been described. Besides autologous materials such as hydroxyapatite or alloplastic substances as tricalcium phosphate have been previously used. A very slow resorption of these materials with rejection has been described. The new ceramic NanoBone® was fabricated in a sol-gel process at 700 °C depositing unsintered hydroxylapatite in a SiO2 structure. This method provides a nano/microstructure of high porosity of the resulting matrix. MATERIAL AND METHODS: 20 patients were reexamined after an average of 2 years and 5 months after obliteration of the open mastoid cavity with NanoBone®. We compared pre- and postoperative findings in terms of otorrhea, frequency of medical consultation, vertigo and otoscopic findings. In 5 patients, in addition, a postoperative CT scan of the temporal bones was used for evaluation of osteoinduction and osteointegration. RESULTS: After obliteration of the open mastoid cavity with NanoBone ® we observed an uneventfully healing. After surgery we achieved a reduction of vertigo, otorrhea and frequency of medical consultations for the single patient. CONCLUSION: The obliteration of an open mastoid cavity with NanoBone ® is a safe alternative method relative to the surgical techniques with autologous materials.

[Optotensometry for measuring the tube function - a feasibility study on a middle ear model]. / Optotensometrie Langzeitmessung der Tubenfunktion - erste Versuche am Mittelohrmodell.

BACKGROUND: The amount of pressure in the middle ear depends mainly on the function of the Eustachian tube. Currently there are no continuous recording techniques measuring Eustachian tube function in clinical context and under physiological conditions over extended periods of time. In this paper we investigate the suitability of an active optic triangulation method on the basis of a projected laser-point-pattern in measuring tympanic membrane movement during pressure variations in a middle ear model. MATERIAL AND METHODS: For projection we used a green semiconductor laser with an output of 1 mW and a diffractive optical element (DOE). As our measured object we used purple latex-foil (Kimberley-Clark (®)), fixed airtight on the cut-off end of a 2 ml syringe-tube. The movement of the foils was measured by an active optic triangulation method. To simulate pathological variations of the tympanic membrane we prepared the latex-foils in specific ways. One foil was perforated and then covered again (simulating tympanic membrane perforation), another one was partly strengthened by sticking a piece of thick, hard paper to it from the inside (simulating calcification). RESULTS: The test-setup, as well as the appliance of pressure-changes worked fine and measurement of foil movement in all the modified foil surfaces was possible. This shows that it is possible to record foil-movement with this system even in tympanic membranes with pathological variations. CONCLUSIONS: In the course of this study we were able to show that it is possible to assess and record foil movement using a system of optic triangulation and to simulate different tympanic membrane pathologies. This could be used both in ENT medicine, as well as in aviation and diving medicine.

[Acoustic-mechanical trauma during cochleostomy: animal experimental studies]. / Akustisch-mechanisches Trauma während einer Cochleostomie: Tierexperimentelle Untersuchungen.

INTRODUCTION: When performing cochlear implant (CI) surgery in ears with residual hearing, cochlear function should be preserved as far as possible. Besides non-traumatic electrode insertion the acoustic-mechanical trauma of the cochleostomy should be minimized. According to experiences from temporal bone preparations the hypothesis that thorough exposition of the endosteal membrane with the drill prior to opening the cochlea might constitute a bigger acoustic mechanical trauma than direct drilling of the inner ear was examined. These experiments were performed in an animal model. MATERIAL AND METHOD: In 12 guinea pigs the cochlear capsule was exposed by opening the bulla under general anesthesia. In 6 animals the fluid-filled cochlea was exposed by careful unilateral abrasion of the bone, whereas on the other ear cochleostomy was performed by direct penetration drilling into the perilymphatic spaces. Hearing tests were performed before and after drilling by measuring evoked brainstem potentials (brainstem electric response audiometry, BERA). In 8 other guinea pig ears abrasive exposition of the cochlea was performed again by only softly touching the otic capsule with the running burr for 10 s. After a hearing test the drilling maneuver was repeated 4 times collectively. Thereby the inner ear was gradually opened from the surface but not deeper into the cochlear lumen. A total of 4 guinea pig ears treated with a single abrasion of 10 s were used as controls. Brain stem measurements were performed accordingly. RESULTS: Hearing loss was lower after a quick direct and deep penetration of the cochlea in comparison to a longer, less invasive opening of the inner ear. Hearing thresholds ascended depending on the duration of the drilling procedure. CONCLUSION: The results support the hypothesis that prolonged drilling of exposed inner ear structures causes more acoustical damage than a direct cochleostomy with the drill.

Detection of tympanic membrane movement using film patch with integrated strain gauge, assessed by optical coherence tomography: experimental study.

OBJECTIVE: We report an ex vivo and in vivo experimental study of a device designed to measure tympanic membrane movement under normal and pathological conditions, assessed using optical coherence tomography. MATERIALS AND METHODS: We designed two types of flexible, round film patch with integrated strain gauge, to be attached to the tympanic membrane in order to measure tympanic membrane movement. Tympanic membrane attachment was assessed using optical coherence tomography. The devices were tested experimentally using an ex vivo model with varying middle-ear pressure. RESULTS: Optical coherence tomography reliably assessed attachment of the film patch to the tympanic membrane, before and after middle-ear pressure changes. Strain gauge voltage changes were directly proportional to middle-ear pressure recordings, for low pressure changes. Tympanic membrane perforations smaller than 2 mm could be sealed off with the film patch. CONCLUSION: Attachment of the film patch with integrated strain gauge to the tympanic membrane was not ideal. Nevertheless, the strain gauge was able to precisely detect small pressure changes within the middle ear, in this experimental model.

[Tongue fixation system for therapy of sleeping disorders. A feasibility study]. / Implantatgebundene Zungenfixierung zur Therapie schlafbezogener Atmungsstörungen. Eine Machbarkeitsstudie.

INTRODUCTION: Forward displacement of the tongue is a verified principle in the therapy of sleep disorders which prevents the tongue from sinking backwards thus avoiding obstruction of the upper respiratory tract during sleep. In this feasibility study a novel oral appliance which connects to a pin implanted within the tongue was investigated. METHODS: A new tongue positioning system using previously implanted tongue piercings as a pivot was developed. By pulling the tongue forward the oral device prevents airway obstruction. In our study we fitted 10 subjects who already had the tongue pierced with the developed oral device. The subjects underwent two nights of polysomnography with and without using the tongue positioning system. Wearing comfort and side effects were evaluated using a questionnaire. Moderate alcohol consumption was used to provoke snoring or apnea in the subjects. Tongue positioning with and without the device was visualized with oropharyngeal MRI. RESULTS: Subjects did not report any discomfort or side effects wearing the device. Subjects showed only moderate snoring or apnea after alcohol consumption and snoring after alcohol consumption was reduced with the device. The average apnea/hypopnea index (AHI) was 0.8/h without the device. Using the device led to an increase of apnea in the subjects. MRI visualization showed that the device did not keep the upper airway space opened by fixing the tongue. CONCLUSION: The effectiveness of the tongue positioning system should be improved by a modification which should be investigated in patients with preexisting sleep disorders.

[Investigation of a new highly porous hydroxyapatite matrix for obliterating open mastoid cavities - application in guinea pigs bulla]. / Untersuchung von hochporösem Knochenaufbaumaterial zur Mastoidhöhlenobliteration- Intrabulläre Applikation beim Meerschweinchen.

BACKGROUND: Many different techniques for obliterating open mastoid cavity have been described. The results after the application of alloplastic materials like Hydroxyapatite and Tricalciumphosphate were poor due to long-lasting resorption. Extrusion of those materials has been described. We investigated the applicability of a new high-porosity ceramic for obliterating large open mastoid cavities and tested it in an animal model (bulla of guinea pig). METHODS: A highly porous matrix (NanoBone) bone-inductor fabricated in a sol-gel-technique was administered unilaterally into the opened bullae of 30 guinea pigs. In each animal the opposite bulla was filled with Bio-Oss, a bone substitute consisting of a portion of mineral bovine bone. Histological evaluations were performed 1, 2, 3, 4, 5 and 12 weeks after the implantation. RESULTS: After the initial phase with an inflammatory reaction creating a loose granulation tissue, we observed the formation of trabeculare bone within the fourth week in both groups. From the fifth week on we found osteoclasts on the surface of NanoBone and Bio-Oss with consecutive degradation of both materials. CONCLUSION: In our animal model study we found beneficial properties of the used bone-inductors NanoBone and Bio-Oss for obliterating open mastoid cavities.

[Lateral pharyngotomy--a rare method of access for removing foreign bodies from the upper third of the esophagus]. / Die laterale Pharyngotomie--ein seltener Zugangsweg zur Fremdkörperentfernung im oberen Osophagusdrittel.

Esophageal foreign body impaction is a serious emergency. Diagnostic workup includes an exact history and physical examination as well as several imaging modalities. The extraction of an esophageal foreign body can be done using nonflexible or flexible esophagoscopy. We report on a 43-year-old patient with typical symptoms of esophageal foreign body impaction. The x-ray overview upon admission showed the adjustment wires of one component of a metal denture in the area of the upper esophagus. Extraction by nonflexible esophagoscopy was rendered impossible because parts of the denture had speared themselves into the esophageal wall. Safe and uncomplicated removal was then performed through a lateral pharyngotomy.

[Myxoma of the middle ear-a rare cause of facial palsy]. / Das Myxom des Mittelohrs als mögliche Ursache einer temporären Fazialisparese.

In case of the co-occurrence of facial palsy and inflammation-like symptoms of the same ear, the differential diagnosis is focused on viral (herpes zoster) or bacterial diseases. We report a patient for whom the surgical exploration of the middle ear revealed a benign tumor: a myxoma. These neoplasias are rare tumors in the head and neck region. The typical tumor site is the atrium of heart. In the ear, the tumor grows slowly and remains asymptomatic unless it irritates structures such as the facial nerve or the vestibular organ. Histologically, the tumor presents a "myxoid" matrix that is rich in acid mucopolysaccarides. The treatment of choice is complete surgical resection. Using the case presented, we discuss the causality between the tumor and the facial palsy, although during the operation the bony canal of the nerve was found to be intact. In any cases with clinically and radiologically unclear findings of the ear in connection with facial palsy, surgical exposure should be considered.

[Investigation of the mechanisms involved in isolated orbital floor fracture. Simulation using a finite element model of the human skull]. / Untersuchungen zum Entstehungsmechanismus der isolierten Orbitabodenfraktur. Simulation am Finite-Elemente-Modell des menschlichen Schädels.

BACKGROUND: Isolated orbital floor fractures make up a significant proportion of all facial injuries, but the mechanism involved in these injuries to the orbital walls (blow-out fractures) has not yet been completely defined. Two theories have been described, which seem to be mutually exclusive. According to the hydraulic pressure theory, the kinetic energy of the blow is transferred via the incompressible eye tissue to the floor of the orbita, which in turn fractures. The buckling force theory, in contrast, explains these fractures as the result of bending and shear stresses arising from kinetic energy act directly on the orbital rim. MATERIALS AND METHODS: With the aim of elucidating the mechanism of injury, we constructed a simplified finite-element model of the human orbita by 3D optical scanning of a human skull obtained after an autopsy examination. We created a generic approximation model based on empiric data derived from femoral fractures and reported in the literature. Several experiments were conducted to test both the above hypotheses by direct and indirect application of kinetic energy. RESULTS: We simulated different types of shear stress with the finite-element model of the skull. The calculated points of maximum pressure were all within the orbital floor. CONCLUSION: The simulation showed that both mechanisms can lead to fractures, as also documented by recent studies. The generation of a finite-element model and simulation of stresses were initially useful in establishing a method. More detailed studies on the empiric data relating to the various structures and more extensive determination and measurement of different skull and/or orbita geometries are needed before we can achieve a model in which the mechanical attributes of the structures involved are reproduced with closer approximation to the real-life situation.

[Isolated fracture of the handle of malleus. A rare differential diagnosis in cases of conductive hearing loss]. / Isolierte Hammergriff-Fraktur. Eine seltene Differenzialdiagnose bei Schallleitungsschwerhörigkeit.

In very rare cases, acute hearing loss can be caused by a fractured long process of the malleus. Such fractures can be due to head traumas, direct injuries of the tympanic membrane or barotraumas. Clinical findings are: abnormal mobility of the manubrium mallei during the Valsalva maneuvre or pneumomassage of the ear drum, conductive hearing loss, abnormal high compliance in the type A tympanigram. We report on a 48 year old female patient who showed typical symptoms and clinical findings, and discuss possible pathogenic factors. In accordance with the literature, we presume that negative pressure in the external ear canal, caused by a rapidly extracted finger (!), might be responsible. At the very onset of hearing loss, the patient noticed a high frequency tinnitus in the affected ear. Surgically, we tried to re-fix the manubrium by splinting it and the adherent parts of the tympanic membrane with cartilage.

Expression of multi-drug resistance genes (mdr1, mrp1, bcrp) in primary oral squamous cell carcinoma.

UNLABELLED: The expression of resistance genes can cause the ineffectiveness of chemotherapeutics for the treatment of cancer. Therefore, known resistance genes were investigated in oral squamous cell carcinoma (OSCC) and the results were compared with clinico-pathological findings. MATERIALS AND METHODS: Fresh frozen samples of 45 primary OSCC were investigated for the expression of mdr1 (p-glycoprotein-mediated multi-drug resistance), mrp1 (multi-drug resistance-related protein) and bcrp (breast cancer-related protein), using a reverse transcriptase PCR. The gene products were revealed immunohistochemically on representative slices of the same tumor sample. The results were compared with TNM stage grouping [SG, (UICC, 1987)], HPV infection and p53 mutations (exons 5-8). RESULTS: The expression of the resistance genes was independent of age, sex, localisation of the tumor, HPV infection and p53 mutations. SG did not correlate to mdr1 and mrp1. On the other hand, bcrp expression increased 2.7-fold between SG III and IV OSCC. Loss of differentiation was associated with an increased expression of mdr1 (p=0.06), mrp1 (p<0.01) and bcrp (p<0.01). The bcrp expression correlated with shorter survival periods. Expression of mrp1 and mdr1 did not correlate positively in a linear pattern. Expression of mdr1 and bcrp moderately positively correlated (p<0.01). DISCUSSION: Multi-drug resistance genes can be up-regulated in OSCC. The expression of at least one of these genes is up-regulated in SG-IV OSCC. Determining these genes could probably support current studies on therapeutic effects in OSCC, e.g. new cytostatic drugs.